Dental articulators are well known in the prior art and are generally used for two purposes. First, as a diagnostic and planning instrument and second, for the technical procedures in constructing prostheses and other restorative appliances. Such restorative appliances typically include full upper and lower dentures, partial dentures, or complete mouth bridge work. In fact, all such restorative appliances are constructed on such dental articulators.
Typically, dental articulators are designed such that the upper half of the instrument, on which is mounted the upper dental arch cast, is movable laterally and back and forth in an attempt to duplicate the movements of the human jaw. These jaw movements which must be duplicated include the retruded contact position, the intercuspal position, as well as the protruded and lateral positions. However, in most of the prior art articulators, these movements of the human jaw are re-created or duplicated inaccurately. This results from the fact that the upper jaw member of the articulator is movable, and the lower jaw member is stationary, whereas in the human jaw, the reverse is true. That is, in the human jaw, the upper jaw is stationary, whereas the lower jaw experiences the protrusive and retrusive movement, as well as lateral movement, about the temporomandibular joint. Therefore, the restorative appliances which are constructed on such dental articulators simulate movement of the mouth in a manner opposite to the actual movement of the mouth so that all registrations are being transposed incorrectly, and the movements of the lower human jaw and the temporomandibular joints are recreated or duplicated inaccurately on such dental articulators.
It is known that the lower human jaw experiences protrusive and retrusive movement, as well as movement in lateral directions from a vertical axis which may be referred to as the centric axis. As the lower human jaw moves to either side of the centric axis, it is moving not only laterally but also downwardly with respect to the upper human jaw. This lateral and downward movement of the lower jaw is caused by the intercuspal engagement of the upper and lower posterior teeth. Accordingly, in order for a dental articulator to accurately duplicate human jaw movements, and in particular, the movement of the lower human jaw in the lateral direction, the articulator must be constructed to simulate all these directions of movement of the lower human jaw which include protrusive and retrusive movement and lateral movement, with the lateral movement being downwardly as the lower jaw moves laterally with respect to the centric axis.
Although prior art articulators have been developed in which the lower jaw portion is movable, the mechanics employed do not accurately simulate the actual movements of the lower human jaw. For example, such articulators do not provide means for mechanically duplicating the dropping of the lower human jaw relative to the upper jaw during lateral movement of the lower jaw.
Broadly, it is an object of the present invention to provide an improved jaw simulator which overcomes one or more of the aforesaid problems. Specifically, it is within the contemplation of the present invention to provide a dental jaw simulator which accurately duplicates the movement of the human jaw and, in particular, the movement of the lower human jaw.
It is a further object of the present invention to provide an improved jaw simulator which accurately duplicates the lateral and downward movement of the lower human jaw as it is moved from side to side with respect to the centric axis.
It is a still further object of the present invention to provide an improved jaw simulator which includes an anterior platform having a plurality of different planes for accurately duplicating the dropping of the lower human jaw during lateral movement.